I ve just spent a day at Porth with a plumbing rod, but not fishing, I plumbed up all the pegs used in the festivals on the the line that most people chuck their feeders, approx 35 turns

I started in the meadow

peg 16 is 15ft, peg 17 to 22 are 14ft deep and pegs 23 and 24 are 13ft deep

In the 30s

peg 32 and 33 are 10ft deep, pegs 34 and 35 are 9ft deep, pegs 36 to 39 are 8ft deep and peg 40 is 7ft

In the 70s and 80s

peg 70 is 16ft deep, this peg is no longer used in festivals but I plumbed it to show the change of depth, peg 71 is 14ft deep, pegs 72 to 79 are 12ft deep, peg 80, where the boat lands,  is 10ft deep, pegs 81 to 89 are 10ft deep and the end peg 90 is 9ft deep.

When you know the depth of water you are fishing into and the other depths along the match stretch it is often possible to work out the reason why the fish are being caught in the the pegs they are.
During the October festivals peg 71 won the lake nearly every day, the big black bream, up to 7lb, stayed in at least 14ft of water and wouldnt venture into shallower swims.

During the recent silverfish festival my dad fished Porth and had catches up to 60lbs by fishing in 19ft of water, anything shallower he could only catch the odd one.
If you fancy fishing Porth for the bream at this time of year the best peg to fish is peg 6 by the bird hide, it is the most comfortable peg on the lake, out of the wind and rain and a short walk, because of this all the pleasure anglers head for it and this peg sees more bait than all the other pegs put together, and the bream know this.
So if you fancy some winter Porth bream head for 19ft of water and preferably peg 6.